Steam turbine testing apparatus



MEASURING & TESTING v July 3, 1945.

c. c. FRANCK 2,379,700

STEAM TURBINE TESTING APPARATUS Filed Oct. 3. 1942 FLUID BRRKE COMPRESSOR BOILER INVENTOR CLRRIII C. Fhnucn.

w. r5. M

ATTORNEY 73. MEASUHmu a lcoimo Patented July 3, 1945 STEAM TURBINE TESTING APPARATUS Clarence C. Franck, Swarthmore, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation oi. Pennsylvania Application October 3, 1942, Serial No. 460,619

4 Claims.

This invention relates to the testing of high temperature and high pressure elastic fluid engines and has for an object to provide improved apparatus for this purpose.

In the testing of steam turbines in a manufacturers shop, severe handicaps are encountered and considerable compromise must be made in the operating steam conditions. Steam conditions for modern marine, industrial, and central station steam turbines vary from 400 pounds per square inch gauge-750 F. to 1800 pounds per square inch gauge-1000 F., while boiler facilities at manufacturing plants are generally 200 pounds per square inch gauge-500 F., or 600 pounds per square inch gauge700 F. By the use of separately fired superheaters, it may be possible to obtain limited quantities of steam at 800 F.

The installation of high pressure and high temperature boilers and interconnected piping is in general economically prohibitive as the use factor associated with shop testing of steam turbines is very low. Also shop testing imposes very severe operating conditions on the boiler since frequent starts and stops and sudden dropping of load, etc., would react unfavorably on the high pressure, high temperature boilers. Also, the generation of high pressure, high temperature steam is not only expensive from a fuel cost point. of view, but involves unusual conditions of operation and high maintenance from high pressure boiler feed pumps and control apparatus.

Also, in testing large, marine, industrial and central station turbines, the possibilities of absorbing load in excess of 3000 horsepower by means of water brakes, electric dynamometers, etc. are limited. Iinterconnections with utility systemsto absorb the load are impractical not only because of the fluctuating character of the load, but due to the hazard involved to the system. As a consequence, in some cases the available steam cannot be utilized since no means for absorbing the load is provided.

It is proposed that for test purposes, the turi bine under test be connected to a steam brake and/or a steam compressor. Steam at normal throttle pressure will be admitted to the turbo- Ecompressor and by varying the compression ratio team at approximately the desired test pressure will be exhausted into a line containing a suitable reducing valve (controlling). This line will be connected to the throttle of the turbine under test. Heat in the form of friction will be added to the steam by bringing the incoming steam through a multi-stage fluid brake. By varying the number of working stages exposed to the incoming steam on its way to the compressor, the amount of heat added (friction loss) at a given internal brake pressure may be controlled. Closer temperature control may be obtained by the addition of a heat exchanger in the line to the turbine throttle.

The steam thus delivered to the turbine under test will flow through the turbine, supply the compression power and/or the heating load and be condensed in the condenser.

.The load on the turbine will consist of the compressor power requirements and the friction load of the heating element. Additional load may be applied by cutting in additional stages of the fluid brake and/or raising the internal pressure of the fluid brake elements not used in the heating cycle. The excess energy thus generated may be dissipated in a heat exchanger (or main condenser). The load on the unit under test may also be controlled in this manner. In order to supply high pressure, high temperature steam for test purposes, the compressor and heating element may be driven by an auxiliary drive.

Therefore, another object of the invention is to provide apparatus whereby relatively low pressure and temperature motive fluid generating apparatus may be used in the testing of elastic fluid engines under relatively high temperature and pressure conditions.

These and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

The single figure is a diagrammatic view of an arrangement of apparatus embodying the features of the present invention.

Referring now to the drawing more in detail, there is shown an elastic fluid turbine I0 adapted to exhaust to a condenser II, the condensed motive fluid being drawn from the condenser hotwell I2 by a pump l3, and directed to a boiler H of the relatively low temperature and pressure type. Motive fluid generated by the boiler It is conducted through a pipe l5 to a multistage fluid brake 16, the fluid passing through the various stages of the brake being withdrawn therefrom through any one of a multiple of outlets ll, l8, I9, and 20, controlled by valves 22, 23, 24, and 25, respectively.

It will be apparent that, by suitable adjustment of the valves, the fluid flowing through the brake may be caused to pass through any selected number of stages thereof, the fluid leaving the brake passing through the conduit 21 to a multiple stage compressor 28, each stage having an outlet 23, 30, 3|, 32, or 33 controlled by valves 35, 36, 31, 38, and 39, respectively. As will be apparent to those skilled in the art, the temperature as well as the pressure of the fluid will be raised by the compressor 28.

Suitable adjustment of the valves provides for flow of fluid through a selected number of stages of the compressor, the fluid leaving the compressor through a conduit 4| and being directed thereby to a heat exchanger 42, to which suitable cooling medium is supplied by a conduit 43 and withdrawn by a conduit 44. Motive fluid is conveyed from the heat exchanger 42 to the turbine H! by the conduit 46, which terminates at the steam chest 48 of the turbine Hi, the flow of steam through the chest being controlled by conventional turbin governor mechanism 49.

In operation, the low pressure and temperature fluid generated in the boiler l4 has its temperature increased to an amount equal to or greater than that desired for testing of the turbine by passing through a selected number of stages of the multi-stage fluid brake Hi. In like manner, the pressure of the elastic fluid is raised by passage thereof through a selected number of stages of the multi-stage compressor 28. Preferably, both the temperature and pressure are raised slightly higher than actually desired for testing purposes and the excess heat and pressure removed by the heat exchanger 42 and the pressure-reducing valve 41. l'nihe arrangement illustrated, the fluid brake i6 and compressor 28 ,are driven by the turbine being tested, thus providing a suitable load for the turbine.

It will be apparent that, if additional load is needed for the turbine, additional stages of the brake and compressor may be used, the excess heat and pressure thereby generated being removed by the heat exchanger and the pressurereducing valve.

Also, the internal pressure of the fluid brake stages may be raised by admitting to the unused stages of the brake l6, higher pressure steam bled from the conduit 4| through the conduit 55, controlled by the valve 56, the excess heat thereby generated being removed by the heat exchanger 42.

It will be appreciated that there may be conditions where sufflcient increase in temperature may be obtained by passing the fluid through the compressor only, and omitting the fluid brake.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What is claimed is:

1. Apparatus for testing a relatively high temperature and pressure elastic fluid turbine, comprising means for generating elastic fluid at temperatures and pressures materially lower than those at which said turbine is to be tested, a multiple-stage brake for increasing the temperature of the elastic fluid generated, a multiplestage compressor for increasing the pressure of the elastic fluid generated, means for directing the elastic fluid generated through selected numbers of the stages of said lggand of said compressor to increase the temperature and pressure of the elastic fluid, and a heat exchanger supplied with the heated and compressed elastic fluid and operable to modify the temperature of such elastic fluid so as to provide elastic fluid of the temperature and pressure required by the turbine, and means for conducting said elastic fluid of the required temperature and pressure to the turbine, the brake and compressor being adapted to be driven by the turbine.

2. Apparatus for testing a relatively high temperature and pressure elastic fluid turbine, comprising means for generating elastic fluid at temperatures and pressures materially lower than those at which said turbine is to be tested, a multiple-stage brake for increasing the temperature of the elastic fluid generated, a multiplestage compressor for increasing the pressure of the elastic fluid generated, means for directing the elastic fluid generated through selected numbers of the stages of said brake and of said compressor to increase the temperature and pressure of the elastic fluid, a heat, exchanger operable to modifyathe temperature of the heated and compressed elastic fluid, a conduit for conducting the elastic fluid from the heat exchanger to the turbine to be tested, and a pressure-reducing valve in said conduit for modifying the pressure of the heated and compressed elastic fluid, said heat exchanger and said reducing valve acting on the heated and compressed elastic fluid to provide the latter at the temperature and pressure required by the turbine to be tested,

brake and compressor being adapted to be d *1- r n y said turbine.

3. Apparatus for testing a relatively high temperature and pressure elastic fluid turbine, comprising means for generating elastic fluid at temperatures and pressures materially lower than those at which said turbine is to be tested, means for increasing the temperature and pressure of the elastic fluid generated, and a heat exchanger supplied with the heated and compressed elastic fluid and operable to modify the temperature of such elastic fluid so as to provide elastic fluid of the temperature and pressure required by the turbine. and means for conducting said elastic fluid of the required temperature and pressure to the turbine, the means for increasing the temperature and pressure of the elastic fluid being adapted to be driven by the turbine.

4. Apparatus for testing a relatively high temperature and pressure elastic fluid turbine, comprising means for generating elastic fluid at temperatures and pressures materially lower than those at which said turbine is to be tested, means for increasing the temperature and the pressure of the elastic fluid generated, a heat exchanger operable to modify the temperature of the heated and compressed elastic fluid, a conduit for conducting the elastic fluid from the heat exchanger to the turbine to be tested, and a pressure reducing valve in said conduit for modifying the pressure of the heated and compressed telastic fluid, said heat exchanger and said reducing valve acting on the heated and compressed elastic fluid to provide the latter at the temperature and pressure required by the turbine to be tested, said means for increasing the temperature and pressure of the elastic fluid being adapted to be driven by said turbine.

CLARENCE C. FRANCK. 

